Support apparatus for movable member and pump apparatus

ABSTRACT

It is an object of the invention to provide a pump apparatus of simple construction with a bearing structure, for which a lubricant is unnecessary. A flow passage for a refrigerant (liquid ammonia) is formed in a housing to provide communication between a suction port and a discharge port, and slide bearing members formed of amorphous carbon are provided in the housing to be fitted into the flow passage to support a rotating shaft. Drive means for rotating the rotating shaft is constituted by a rotor, which is fitted into the flow passage and provided with the rotating shaft, and a stator, which is provided outside the housing to surround the rotor, and a pump body is provided midway the flow passage and connected to the rotating shaft to pump a fluid.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The invention relates to a support apparatus provided with amember for displaceably supporting a movable member such as a rotatingshaft, and a pump apparatus.

[0003] 2. Description of the Related Art

[0004] Space equipment such as artificial satellites, space stations orthe like, and equipment used in outer space include many kinds of drivemechanisms, in which a support apparatus, such as ball-and-rollerbearing appartuses, ball screw apparatuses, linear guide apparatuses andthe like, for displaceably supporting a movable member is used. Fluorogrease is used as a lubricant in a support apparatus for use on earth,but evaporates in outer space to be responsible for contamination onvarious equipment and decomposition due to radioactive ray, so cannot beused there. In a support apparatus for equipment used in outer space,molybdenum dioxide, lead or silver is used, which is low in torque andstable.

[0005] As described above, equipment used in outer space, in particular,equipment used over a long term in artificial satellites, space stationsor the like are exceedingly difficult in exchange of parts, and requiredof high durability. A support apparatus for supporting a movable memberprovided in such equipment is desirably made simple in construction forthe purpose of less failure, and constructed to dispense with lubricantfor prevention of degraded performance due to secular change.

SUMMARY OF THE INVENTION

[0006] It is an object of the invention to provide a support apparatus,which is simple in construction and dispenses with lubricant.

[0007] Also, it is an object of the invention to provide a pumpapparatus, which is simple in construction and provided with a bearingstructure for supporting a rotating shaft, which dispenses withlubricant.

[0008] The invention provides a support apparatus for displaceablysupporting a movable member, comprising slide members for slidablysupporting the movable member, the slide members being formed ofamorphous carbon.

[0009] According to the invention, a movable member can be supported byslide members formed of amorphous carbon. Amorphous carbon is high inabrasion resistance and possesses a low frictional property called aself-lubricating property, and slide members formed of amorphous carbonare used to smoothly slide relative to a movable member to, withoutusing lubricant, enable supporting the movable member so that themovable member can be smoothly displaced. Accordingly, it is possible toobtain a support apparatus that is simple in construction and supports amovable member without the use of lubricant, to enhance durability ofthe support apparatus.

[0010] In the invention, it is preferable that the movable membercomprises a rotating shaft and the slide members are slide bearingmembers for rotatably supporting the rotating shaft.

[0011] According to the invention, the slide bearing members formed ofamorphous carbon can support the rotating shaft. Thereby, it is possibleto reduce a gap between the rotating shaft and the slide bearing membersand rotatably support the rotating shaft so as to cause stable rotationof the rotating shaft.

[0012] In the invention, it is preferable that the slide members arearranged in a space in which a fluid is contained.

[0013] According to the invention, the slide members are formed ofamorphous carbon and possess chemical resistance, so they are notsubjected to chemical change by a fluid even when being provided in aspace in which a fluid is contained. Besides, even if the fluid is one,either strong acid or strong base, liable to chemically affect a matingmember, the slide members are not subjected to chemical change by thefluid. Thereby, the slide members can preserve the function as slidemembers over a long term without being damaged by the fluid.Accordingly, the slide members can be suitably used in fluid flowpassages.

[0014] In the invention, it is preferable that a gap between the movablemember and the slide members is dimensioned to allow entry of the fluiddue to the capillary phenomenon.

[0015] According to the invention, a fluid in the space enters betweenthe movable member and the slide members. The slide members formed ofamorphous carbon are not restricted in lubricant as in the case of slidemembers of metal, but can use a wide variety of fluids as lubricant. Asdescribed above, while lubricant is essentially unnecessary, the use oflubricant makes it possible to support the movable member in a furthersmoothly displaceable manner. Accordingly, a fluid in the gap can beused as lubricant so that a supporting state can be achieved to realizethe smooth displacement of the movable member.

[0016] In the invention, it is preferable that the fluid is liquidammonia.

[0017] According to the invention, the slide members possess chemicalresistance, and are not subjected to chemical change even when a fluidis liquid ammonia, so that they can preserve the function as slidemembers over a long term. Moreover, it is possible to make use of liquidammonia as a favorable lubricant. Accordingly, the slide bearing memberscan be favorably used in a space, in which liquid ammonia is contained.

[0018] In the invention it is preferable that the pump apparatus ismounted on equipment used in outer space.

[0019] According to the invention, the support apparatus can be enhancedin durability, so that it is suitably usable for equipment, such asartificial satellites, space stations or the like, which are used inouter space, of which parts are difficult to exchange.

[0020] The invention provides a pump apparatus comprising a rotatingshaft, slide bearing members formed of amorphous carbon, for rotatablysupporting the rotating shaft, drive means for drivingly rotating therotating shaft, and a pump body connected to the rotating shaft, forpumping a fluid.

[0021] According to the invention, the drive means is used to drive therotating shaft to drive the pump body connected to the rotating shaft todischarge a fluid. The rotating shaft is rotatably supported by abearing apparatus having slide bearing members. The slide bearingmembers are formed of amorphous carbon. Amorphous carbon is high inabrasion resistance and possesses a low frictional property called aself-lubricating property, and slide bearing members formed of amorphouscarbon are used to smoothly slide relative to the rotating shaft to,without using lubricant, enable supporting the rotating shaft so thatthe rotating shaft can be smoothly rotated. Accordingly, it is possibleto obtain a bearing apparatus which is simple in construction andsupports the rotating shaft without the use of lubricant to enhancedurability of the bearing apparatus, thus of the pump apparatus.

[0022] In the invention it is preferable that the pump apparatus furthercomprises a housing having a fluid flow passage which providescommunication between a suction port and a discharge port, and that therotating shaft is arranged in the housing, the slide bearing members arefitted in the fluid flow passage in the housing, the drive meanscomprises a rotor fitted in the fluid flow passage to be provided on therotating shaft and a stator provided outside the housing to surround therotor, and the pump body is provided midway the fluid flow passage.

[0023] According to the invention, the drive means is used to drive therotating shaft to drive the pump body connected to the rotating shaft sothat a fluid sucked through a suction port is made to flow down the flowpassage to be discharged through a discharge port. In this pumpapparatus, the rotating shaft, the slide bearing members and the rotorare fitted into the flow passage. In this manner, the provision of therotating shaft, the slide bearing members and the rotor in the flowpassage eliminates the need of providing rotating constituents bothinside and outside the flow passage through the housing, so that thewhole pump apparatus can be made favorable in sealing quality relativeto leakage of the fluid, the sealing construction can be made simple,and the pump apparatus can be made small in size.

[0024] With such construction, the slide bearing members are formed ofamorphous carbon and possess chemical resistance, so they are notsubjected to chemical change by a fluid even when being provided in aspace in which a fluid is contained. Besides, even if the fluid is one,either strong acid or strong base, liable to chemically affect a matingmember, the slide members are not subjected to chemical change by thefluid. Thereby, the slide bearing members can preserve the function asslide bearing members over a long term without damage by the fluid.

[0025] In the invention, it is preferable that a gap between therotating shaft and the slide bearing members is dimensioned to allowentry of the fluid due to the capillary phenomenon.

[0026] According to the invention, a fluid in the flow passage entersbetween the rotating shaft and the slide bearing members. The slidebearing members formed of amorphous carbon are not restricted inlubricant as in the case of slide bearing members of metal, but can usea wide variety of fluids as lubricant. As described above, whilelubricant is essentially unnecessary, the use of lubricant makes itpossible to support the rotating shaft in a further smoothlydisplaceable manner. Accordingly, the fluid in the flow passage can beused as lubricant and so a pump apparatus can be achieved to provide forfurther smooth rotation of the rotating shaft.

[0027] In the invention it is preferable that the pump apparatus is apump for circulating a refrigerant and the fluid is liquid ammonia asrefrigerant.

[0028] According to the invention, the slide bearing members possesschemical resistance, and are not subjected to chemical change even whenthe fluid is liquid ammonia, so that they can preserve the function asslide bearing members over a long term. Moreover, the slide bearingmembers can make use of liquid ammonia as a favorable lubricant. Withoutthe use of flon gas, for the sake of global environmental protection,such liquid ammonia is used as a refrigerant favorably in the pumpapparatus, in which the refrigerant is circulated.

[0029] Also, liquid ammonia as refrigerant can be used to cool therotating shaft, the slide bearing members and the rotor and to maintaina stable performance of the pump.

[0030] In the invention it is preferable that the pump body is formed ofamorphous carbon.

[0031] According to the invention, the pump body is formed of amorphouscarbon, and so is hard to be susceptible of chemical influences, wherebyit is possible to realize a favorable pump apparatus that keeps thefunction of the pump body over a long term.

[0032] In the invention, it is preferable that the slide bearing membersare radial bearings to bear radial load of the rotating shaft, and thepump body is formed of amorphous carbon to bear thrust load of therotating shaft.

[0033] According to the invention, formation of the pump body ofamorphous carbon can have the pump body fulfilling the function asthrust bearings and bearing thrust load of the rotating shaft.Therefore, load on the slide bearing members can be reduced. In thismanner, load is imposed on the pump body to make it possible to reducethe slide bearing members in size and enhance durability of the pumpapparatus.

[0034] In the invention, it is preferable that the pump apparatus ismounted on equipment used in outer space.

[0035] According to the invention, the pump apparatus can be enhanced indurability, so that it is suitably usable for equipment, such asartificial satellites, space stations or the like, which are used inouter space, of which parts are difficult to exchange.

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Other and further objects, features, and advantages of theinvention will be more explicit from the following detailed descriptiontaken with reference to the drawings wherein:

[0037]FIG. 1 is a cross sectional view showing a pump apparatus 1according to an embodiment of the invention;

[0038]FIG. 2 is a cross sectional view of the pump apparatus 1 as viewedfrom above of FIG. 1;

[0039]FIG. 3 is a left side view of the pump apparatus 1 as viewed fromleftward of FIG. 1;

[0040]FIG. 4 is a right side view of the pump apparatus 1 as viewed fromrightward of FIG. 1;

[0041]FIG. 5 is a front view showing a cylindrical-shaped member 11constituting a housing 3;

[0042]FIG. 6 is a right side view of the cylindrical-shaped member 11 asviewed from rightward of FIG. 5;

[0043]FIG. 7 is a cross sectional view showing a pump chamber formingmember 12 constituting the housing 3;

[0044]FIG. 8 is a plan view of the pump chamber forming member 12 asviewed from above of FIG. 7;

[0045]FIG. 9 is a left side view of the pump chamber forming member 12as viewed from leftward of FIG. 7;

[0046]FIG. 10 is a right side view of the pump chamber forming member 12as viewed from rightward of FIG. 7;

[0047]FIG. 11 is a cross sectional view of a suction port forming member13 constituting the housing 3;

[0048]FIG. 12 is a left side view of the suction port forming member 13as viewed from leftward of FIG. 11;

[0049]FIG. 13 is a right side view of the suction port forming member 13as viewed from rightward of FIG. 11;

[0050]FIG. 14 is a cross sectional view showing a discharge port formingmember 14 constituting the housing 3;

[0051]FIG. 15 is a right side view of the discharge port forming member14 as viewed from rightward of FIG. 14;

[0052]FIG. 16 is a front view showing a rotating shaft 4;

[0053]FIG. 17 is a left side view of the rotating shaft 4 as viewed fromleftward of FIG. 16;

[0054]FIG. 18 is a cross sectional view showing slide bearing members 5;

[0055]FIG. 19 is a left side view of the slide bearing members 5 asviewed from leftward of FIG. 18;

[0056]FIG. 20 is a front view showing an inner gear 60;

[0057]FIG. 21 is across sectional view taken along the cutting planeline S21-S21 in FIG. 20;

[0058]FIG. 22 is a front view showing an outer gear 61;

[0059]FIG. 23is across sectional view taken along the cutting plane lineS23-S23 in FIG. 22;

[0060]FIG. 24 is a cross sectional view showing a pump body 10 inenlarged scale;

[0061]FIG. 25 is a cross sectional view of the pump body 10 as viewedfrom leftward of FIG. 24;

[0062]FIG. 26 is an exploded, perspective view showing the pump body 10;

[0063]FIG. 27 is a cross sectional view showing an apparatus formeasuring coefficients of friction;

[0064]FIGS. 28A and 28B are graphs showing results of tests formeasuring coefficients of friction;

[0065]FIG. 29 is a cross sectional view showing an apparatus formeasuring wear in the air;

[0066]FIGS. 30A and 30B are graphs showing results of tests formeasuring wear in the air;

[0067]FIG. 31 is a cross sectional view showing an apparatus formeasuring wear in the water;

[0068]FIGS. 32A and 32B are graphs showing results of tests formeasuring wear in the water;

[0069]FIG. 33 is a graph showing wear coefficients of various materialsincluding AC;

[0070]FIG. 34 is a graph showing coefficients of thermal expansion ofvarious materials including AC;

[0071]FIG. 35 is a graph showing bulk densities of various materialsincluding AC;

[0072]FIG. 36 is a graph showing melting points or temperatures ofthermal deformation of various materials including AC;

[0073]FIG. 37 is a graph showing the relationship between dischargepressure and flow rate of the pump apparatus 1 making use of water at5.5° C.;

[0074]FIG. 38 is a graph showing the relationship between dischargepressure and flow rate of the pump apparatus 1 making use of ethylether;

[0075]FIG. 39 is a graph showing the relationship between dischargepressure and flow rate of the pump apparatus 1 making use of liquidammonia at 8° C.;

[0076]FIG. 40 is a graph showing the relationship between dischargepressure and flow rate of the pump apparatus 1 making use of ethyl etherat 10° C.;

[0077]FIG. 41 is a graph showing the relationship between input power toa drive means and flow rate of the pump apparatus 1 making use of ethylether at 10° C.; and

[0078]FIG. 42 is a graph showing the relationship between number ofrevolution and flow rate of the pump apparatus 1 making use of ethylether at 10° C.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0079] Now referring to the drawings, preferred embodiments of theinvention are described below.

[0080]FIG. 1 is across sectional view showing a pump apparatus 1according to an embodiment of the invention, FIG. 2 being a crosssectional view showing the pump apparatus 1 as viewed from above FIG. 1,FIG. 3 being a left side view showing the pump apparatus 1 as viewedfrom leftward of FIG. 1, and FIG. 4 being a right side view showing thepump apparatus 1 as viewed from rightward of FIG. 1. The pump apparatus1 is an apparatus for feeding a liquid being a fluid, the apparatusbeing mounted on, for example, space equipment such as artificialsatellites, space stations or the like, and equipment used in outerspace outside the stratosphere, and serving to circulate a refrigerant,which makes heat exchange with other apparatuses mounted on theequipment. The pump apparatus 1 comprises a housing 3 formed with arefrigerant flow passage 2, a rotating shaft 4 provided in the housing3, a bearing structure 6 having slide bearing members 5, which rotatablysupport the rotating shaft 4, a motor 9 having a rotor 7 and a stator 8,and a pump body 10 connected to the rotating shaft 4. For the sake ofglobal environmental conservation, fron gas is not used for therefrigerant but liquid ammonia is used.

[0081] Assembled to the housing 3 are a cylindrical-shaped member 11shown in FIGS. 5 and 6, a pump chamber forming member 12 shown in FIGS.7, 8, 9 and 10, a suction port forming member 13 shown in FIGS. 11, 12and 13, and a discharge port forming member 14 shown in FIGS. 14 and 15.The cylindrical-shaped member 11 is thin-walled and cylindrical-shaped,and both axial ends 15 and 16 thereof are formed with a plurality of,for example, circumferentially three through holes 17, 18, respectively.

[0082] The pump chamber forming member 12 is formed at its one axial end19 with an axially opened fitting recess 20, in which a pump chamber 22having a cylindrical-shaped, inner peripheral surface is formed to becontiguous to the other axial end 21 of the fitting recess 20. Thefitting recess 20 is coaxial with an axis L12 of the pump chamberforming member 12, and the pump chamber 22 is of a smaller diameter thanthat of the fitting recess 20 to be formed offset from the axis L12 ofthe pump chamber forming member 12.

[0083] Also, the pump chamber forming member 12 is formed at the otheraxial end 21 with an axially opened bearing recess 23, which is coaxialwith the axis L12 of the pump chamber forming member 12, and with ashaft insertion hole 24, which passes through the pump chamber formingmember 12 along the axis L12 to provide communication between the pumpchamber 22 and the bearing recess 23. Further, the pump chamber formingmember 12 is formed with an inside pump port 25, which is contiguous tothe pump chamber 22 on a side of the other axial end 21, and an insidepump passage 26, which is offset from the axis L12 of the pump chamberforming member 12 to pass in parallel to the axis L12. The inside pumpport 25 is formed in an arc extending about an axis of the pump chamber22, that is, an axis L22 of an inner peripheral surface facing the pumpchamber 22, the inside pump passage 26 being axially opened at the otheraxial end 21 of the pump chamber forming member 12.

[0084] Such pump chamber forming member 12 is inserted into thecylindrical-shaped member 11 from a side of the other axial end 21, andmounted to the one axial end 15 of the cylindrical-shaped member 11 byinserting bolts 28 through the respective through holes 17 and screwingthe same to the pump chamber forming member 12 with the use of threadedholes 27. In this state, an O-ring 31 is provided between thecylindrical-shaped member 11 and the pump chamber forming member 12 tobe fitted into an annular groove 30, which is formed in an outerperipheral portion at the other axial end 21 of the pump chamber formingmember 12, thus attaining sealing.

[0085] Formed in the suction port forming member 13 are an axiallyopened suction port 33, which is disposed at a one axial end 32 to beoffset from an axis L13 of the suction port forming member 13, and asuction passage 34 contiguous to the suction port 33 to axially extendin parallel to the axis L13 of the suction port forming member 13, thesuction passage 34 being axially opened at the other axial end 35 of thesuction port forming member 13. Also, formed in the pump chamber formingmember 12 are an axially opened bearing recess 36, which is disposed atthe other axial end 35 to be coaxial with the axis L13 of the suctionport forming member 13, and a shaft insertion recess 37 contiguous tothe bearing recess 36 to extend near a center in the axial directionalong the axis L13 of the suction port forming member 13.

[0086] Such suction port forming member 13 is inserted into thecylindrical-shaped member 11 from a side of the other axial end 35, andmounted to the other axial end 16 of the cylindrical-shaped member 11 byinserting bolts 38 through the respective through holes 18 and screwingthe same to the suction port forming member 13 with the use of threadedholes 39. In this state, an O-ring 41 is provided between thecylindrical-shaped member 11 and the suction port forming member 13 tobe fitted into an annular groove 40, which is formed in an outerperipheral portion at the other axial end 35 of the suction port formingmember 13, thus attaining sealing.

[0087] Formed in the discharge port forming member 14 is an axiallyopened discharge port 43, which is disposed at the one axial end 42thereof to be offset from an axis L14 of the discharge port formingmember 14. Further, formed in the discharge port forming member 14 is anoutside pump port 45, which is disposed at the other axial end 44thereof to be offset from the axis L14 of the discharge port formingmember 14. The outside pump port 45 is disposed in a positioncorresponding to the discharge port 43 with respect to in acircumferential direction to extend circumferentially arcuately.Further, formed in the discharge port forming member 14 is a dischargepassage 46, which is offset from the axis L14 of the discharge portforming member 14 to extend through the discharge port forming member 14in parallel to the axis L14.

[0088] Such discharge port forming member 14 has the other axial end 44fitted into the fitting recess 20 of the pump chamber forming member 12to plug the pump chamber 22 in the axial direction. The pump chamberforming member 12 is provided at its one axial end 19 with a flange 47,which extends radially outward and is formed with a plurality of (forexample, four) threaded holes 46, and the discharge port forming member14 is provided at its one axial end 42 with a flange 49, which extendsradially outward and is formed with a plurality of (for example, four)through holes 48. Bolts 50 inserted through the respective through holes48 are screwed into the flange 47 with the use of the threaded holes 46,whereby the discharge port forming member 14 is mounted to the pumpchamber forming member 12 with its other axial end 44 fitted into thefitting recess 20. In this state, an O-ring 52 is provided between thepump chamber forming member 12 and the discharge port forming member 14to be fitted into an annular groove 51, which is formed in an outerperipheral portion at the other axial end 44 of the discharge portforming member 14, thus attaining sealing.

[0089] In this manner, the housing 3 is constructed, in which state theaxis L1 of the cylindrical-shaped member 11, the axis L12 of the pumpchamber forming member 12, the axis L13 of the suction port formingmember 13, and the axis L14 of the discharge port forming member 14 arein accord with the axis L3 of the housing 3. A rotor chamber 55 isformed in the housing 3 to be disposed between the pump chamber formingmember 12 and the suction port forming member 13, and the suctionpassage 34 and the inside pump passage 26 are communicated to the rotorchamber 55. Accordingly, the suction port 33 and the discharge port 43are formed in the housing 3, and the flow passage 2 is formed tocommunicate with these ports 33, 43. The flow passage 2 of a refrigerantbeing a fluid is formed by connection of at least the suction passage34, the rotor chamber 55, the inside pump passage 26, the inside pumpport 25, the pump chamber 22, the outside pump port 45 and the dischargepassage 46 in this order. Such housing 3 is composed of, for example,stainless steel.

[0090] Provided within such housing 3 is the rotating shaft 4 being amovable member shown in FIGS. 16 and 17, the rotating shaft 4 beingrotatably supported by the slide bearing members 5, which are supportmembers shown in FIGS. 18 and 19. The rotating shaft 4 is formed ofstainless steel to be columnar-shaped, and its one axial end 69 ispartially cut away in a circumferential direction to be oval-shaped incross section to be adapted for latching. In this embodiment, the twoslide beating members 5 are provided, each of which is formed ofamorphous carbon to be made in the form of a short cylinder.

[0091] The respective slide bearing members 5 are press fitted into andfixed to the bearing recess 23 of the pump chamber forming member 12 andthe bearing recess 36 of the suction port forming member 13 in such away that the axis L5 is in accord with the axis L3 of the housing 3. Inthis manner, the respective slide bearing members 5 are held by andprovided in the housing 3 to be exposed to the rotor chamber 55, whichconstitutes a part of the flow passage 2. In a state of being insertedthrough the respective slide bearing members 5, the rotating shaft 4 isinserted through the shaft insertion hole 24 of the pump chamber formingmember 12 with one axial end thereof disposed in the pump chamber 22 andthe other axial end thereof 56 inserted and disposed in the shaftinsertion recess 37.

[0092] In this manner, the rotating shaft 4 is rotatably supported aboutthe axis L3 from radially outward by the slide bearing members 5 withthe axis L4 in accord with the axis L3 of the housing 3. Thus therespective slide bearing members 5 are radial bearings for supportingthe rotating shaft 4 in a radial direction. When the rotating shaft 4has an outer diameter of, for example, 2 mm, a radial gap δ between therotating shaft 4 and the respective slide bearing members 5 is at least0.75 μm and at most 2 μm with an inner diameter of the slide bearingmembers 5 being selected to be at most 2.015 mm and at least 2.004 mm.Such gap is dimensioned to allow a refrigerant in the rotor chamber 55to enter thereinto due to the capillary phenomenon. Thus the gap isformed to be extremely small, thus enabling stably supporting therotating shaft 4.

[0093] Fitted in the pump chamber 22 as shown in FIGS. 24 and 25 are aninner gear 60 shown in FIGS. 20 and 21, and an outer gear 61 shown inFIGS. 22 and 23. The inner gear 60 is formed at an outer peripherythereof with a plurality of (for example, four) teeth 62. The outer gear61 is substantially cylindrical-shaped and formed at an inner peripherythereof with teeth 63, the number of which is more by one than that ofthe teeth 62 of the inner gear 60.

[0094] As shown in FIG. 26, the inner gear 60 is fixed to one end 69 ofthe rotating shaft 4 in a state, in which a spacer 65 in the form of asubstantially elliptical cylinder is press fitted onto one end 55 of therotating shaft 4 and further the inner gear is press fitted onto thespacer 65. Accordingly, the inner gear 60 has its axis L60 aligned withthe axis L3 of the housing 3. The outer gear 61 is fitted onto the innergear 60 in a state of meshing with the inner gear 60. The outer gear 61has an outer diameter slightly smaller than an inner periphery of thepump chamber 22 and has its axis L61 aligned with the axis L22 of thepump chamber 22 to be eccentric relative to the inner gear 60.

[0095] These inner gear 60, outer gear 61 and a portion surrounding thepump chamber 22 constitute a displacement pump, concretely a pump body10 being a trochoidal gear pump. With the pump body 10, a plurality ofpressure chambers are defined between the inner gear 60 and the outergear 61, so that when the inner gear 60 is rotated by rotation of therotating shaft 4, the outer gear 61 correspondingly rotates to varyvolumes of the pressure chambers. The pressure chambers are communicatedto the inside pump port 25 in a position where volumes become large, andare made contiguous to the outside pump port 45 in a position wherevolumes become small.

[0096] Also, the inner gear 60 and the outer gear 61 are formed ofamorphous carbon. The inner gear 60 also functions as a thrust bearingfor axially supporting the rotating shaft 4.

[0097] The rotor 7 fixed to the rotating shaft 4 and formed of a magnetis provided in the rotor chamber 55, and the stator 8 is provided in aposition surrounding the rotor 7 outside the housing 3. Drive means 9 isconstituted by the rotor and the stator. The stator 8 includes a coil,which is electrically energized to impart torque to the rotor 7 due tothe magnetic action between it and the rotor 7, thus rotatingly drivingthe rotating shaft 4 to rotate the inner gear 60 to drive the pump body10. Thereby, the pump body 10 causes a refrigerant to be sucked from thesuction port 33 to flow down the flow passage 2 to be discharged fromthe discharge port 43.

[0098] Amorphous carbon (referred below to as “AC”) is also called glasscarbon, and is amorphous carbon to have a property of low coefficient offriction. FIGS. 28A and 28B show results of a test, in which acoefficient of friction was measured by sliding for example, astationary test piece 70 formed of AC shown in FIG. 27 on an outerperiphery of a rotating test piece formed of high carbon chromiumbearing steel (SUJ2) or silicon nitride (Si₃N₄). In this manner, membersformed of AC exhibit small coefficients of friction even when nolubricant is existent between them and other members, and furtherexhibit extremely small coefficients of friction when a lubricant isexistent, irrespective of a kind of the lubricant.

[0099] Also, members formed of AC have a property that coefficients offriction are small. FIGS. 30A and 30B show results of a test, in whichdepth of severe-mild wear was measured by rotating, pushing and slidinga test shaft 74, which was formed of stainless steel and had asemi-spherical shaped tip end, on, for example, a stationary test piece73 formed of AC and shown in FIG. 29. Also, FIGS. 32A and 32B showresults of a test, in which severe-mild wear and surface roughness weremeasured by rotating, pushing and sliding a test piece 75, which wasformed of alumina ceramics, on a test piece composed of AC or severalcompounds in water as shown in FIG. 31. As indicated by these testresults and a graph in FIG. 33, members formed of AC are small incoefficient of friction as compared with other members formed of othermaterials, and so hard to abrade, and are small in surface roughnesseven in the case of wearing.

[0100] Further, members formed of AC are small in coefficient of thermalexpansion as shown in FIG. 34, small in bulk density as shown in FIG.35, and high in melting point or temperature thermal deformation to behigh in heat resistance as shown FIG. 36.

[0101] Also, Table 1 shows properties of AC and other materials incombination, Table 2 showing properties of AC, Table 3 showing contentsof impurities in the slide bearing members 5 formed of AC, inner gear 60and the outer gear 61, and Table 4 showing hydrofluoric acid resistanceof the slide bearing members 5 formed of AC, inner gear 60 and the outergear 61. TABLE 1 ductility coefficient fusing Young's (breaking ofthermal bonding point or strength modulus strain) expansion densitymaterial structure strength Tg (K) (MPa) (GPa) (%) ×10⁻⁶/° C. (Mg/m³)ceramics aggregation ionic bond high large large small small small to ofand 800-3500 1000-20000 70-700 10° 0-10 medium compound- covalent 1-5based bond crystal metal crystal of metallic medium medium medium mediummedium medium to simple bond 400-3400 400-3000 70-400 10⁰-10² 4-40 largesubstance or 2-20 solid solution organic amorphous covalent low smallsmall medium large small polymer substance bond 350-600 10-100 10 or10⁰-10³ 10² or more 1-2 composed of less molecular chain amorphoussimple, covalent 2600 200 30 1 3 1.5 carbon amorphous bond substanceisotropic crystal covalent 3600 40-90 10-15 10⁰ 4.6-6.5 1.7-1.9 high-aggregation bond density of simple graphite substance

[0102] TABLE 2 * properties gas Coefficient heat Charpy ash bulk trans-bending tensil tensil elastic Resist- of thermal con- impact con-density porosity mittance strength strength elon- modulus ibilityexpansion ductivity Shore strength tent g/cm³ % cm²/sec MPa MPa gation %GPa μΩ · cm ×10⁻⁶/K W/m · K hardness kg · cm/cm² ppm 1.46-1.60 0.6-0.92.4 × 10⁻¹² 120 (40) (1.1) 30 4400- 3.0 5-8 127-130 (2.1-3.6) 20 4500

[0103] TABLE 3 * analytical value of ash content (impurities) total ashimpurities Al Ca Cr Ba Fe Co Mn Sr Ni V Si content con- ND 1.5 <0.1 <0.12.5 0.1 ND <0.1 1.4 <0.1 2.7 20 centration (ppm)

[0104] TABLE 4 hydrofluoric acid resistance impurities Al Ca Cr Cu Fe KMg Na Ni Pb Si con- 0.14 <1 <0.1 <0.2 <0.5 <1 <0.05 0.3 <0.05 <0.2 <1000centration (ppm)

[0105] As apparent from the above-mentioned respective test results andthe respective Tables 1 to 4, AC possesses properties such as lightness,low coefficient of thermal expansion, high rigidity, high heatresistance, gas non-permeability, high hardness, abrasion resistance,low coefficient of friction, compact homogeneous structure, chemicalresistance and carbon powder non-falling or the like, and is muchsuitable as a material for members, which slide relative to othermembers. That is, AC can be much suitably used as the above-mentionedslide bearing member.

[0106]FIG. 37 is a graph showing the relationship between dischargepressure and flow rate of the pump apparatus 1 making use of water at5.5° C., FIG. 38 being a graph showing the relationship betweendischarge pressure and flow rate of the pump apparatus 1 making use ofethyl ether, and FIG. 39 being a graph showing the relationship betweendischarge pressure and flow rate of the pump apparatus 1 making use ofliquid ammonia at 8° C. Also, FIG. 40 is a graph showing therelationship between discharge pressure and flow rate of the pumpapparatus 1 making use of ethyl ether at 10° C., FIG. 41 being a graphshowing the relationship between input power to the drive means and flowrate of the pump apparatus 1 making use of ethyl ether at 10° C., FIG.42 being a graph showing the relationship between number of revolutionand flow rate of the pump apparatus 1 making use of ethyl ether at 10°C. In addition, FIGS. 40 to 42 show results in the case of using ethylether easy to handle while the inventors of this application haveconfirmed that similar results can be obtained in the case of usingliquid ammonia.

[0107] Table 5 shows results of the performance test of the pumpapparatus 1 making use of ethyl ether at temperature of 10° C., Table 6showing results of the performance test of the pump apparatus 1 makinguse of ethyl ether at temperature of 20° C., Table 7 showing results ofthe performance test of the pump apparatus 1 making use of ethyl etherat temperature of 40° C., Table 8 showing results of the performancetest of the pump apparatus 1 making use of ethyl ether at temperature of60° C., Tables 9 and 10 showing results of the performance test of thepump apparatus 1 making use of ethyl ether at temperature of 60° C., andTables 11 to 13 showing results of the performance test of the pumpapparatus 1 making use of liquid ammonia at 8° C. TABLE 5 number ofinput side discharge side differential current input revolution pressurepressure pressure flow rate A W msec rpm V gf/cm² V gf/cm² gf/cm² Vcc/min kg/h 0.188 3.01 3.74 4011 −0.196 −284 −0.075 −109 175 3.89 23310.12 0.209 3.34 4.02 3731 −0.193 −279 −0.020 −29 250 3.30 198 8.600.218 3.49 4.14 3623 −0.193 −280 0.003 5 285 2.85 171 7.42 0.235 3.764.38 3425 −0.190 −274 0.044 64 338 2.13 128 5.54 0.279 4.46 5.14 2918−0.180 −261 0.118 171 431 0.00 0 0.00

[0108] TABLE 6 number of input side discharge side differential currentinput revolution pressure pressure pressure flow rate A W msec rpm Vgf/cm² V gf/cm² gf/cm² V cc/min kg/h 0.167 2.67 3.46 4335 −0.096 −1370.044 63 201 4.19 251 10.76 0.196 3.14 3.84 3906 -0.086 -123 0.148 211334 3.08 185 7.91 0.211 3.38 4.08 3676 -0.079 -112 0.209 298 410 2.07124 5.32 0.226 3.62 4.38 3425 -0.073 -104 0.255 363 467 1.02 61 2.610.243 3.89 4.56 3289 -0.071 -102 0.289 413 515 0.00 0 0.00

[0109] TABLE 7 number of input side discharge side differential currentinput revolution pressure pressure pressure flow rate A W msec rpm Vgf/cm² V gf/cm² gf/cm² V cc/min kg/h 0.197 3.15 3.88 3866 0.246 3420.381 530 188 4.40 264 11.02 0.206 3.30 4.06 3695 0.236 328 0.421 585257 3.68 221 9.20 0.215 3.44 4.16 3606 0.243 338 0.455 632 294 2.99 1797.48 0.225 3.60 4.38 3425 0.246 342 0.486 676 334 2.29 137 5.73 0.2383.81 4.56 3289 0.255 354 0.530 737 383 1.39 84 3.48 0.262 4.19 5.00 30000.256 356 0.576 801 445 0.00 0 0.00

[0110] TABLE 8 number of input side discharge side differential currentinput revolution pressure pressure pressure flow rate A W msec Rpm Vgf/cm² V gf/cm² gf/cm² V cc/min kg/h 0.206 3.30 4.08 3676 0.789 10650.943 1273 208 4.23 254 10.27 0.215 3.44 4.22 3555 0.785 1059 0.969 1308249 3.60 216 8.74 0.220 3.52 4.34 3456 0.787 1062 0.996 1345 283 3.06184 7.44 0.236 3.78 4.60 3261 0.804 1085 1.056 1425 340 2.03 122 4.930.248 3.97 4.84 3099 0.820 1107 1.102 1488 381 1.13 68 2.74 0.269 4.305.20 2885 0.783 1057 1.096 1480 423 0.00 0 0.00

[0111] TABLE 9 number of input side discharge side differential currentinput revolution pressure pressure pressure flow rate A W Hz rpm Vgf/cm² V gf/cm² gf/cm² V cc/min kg/h 0.215 3.44 59.10 3546 −141 131 272310 0.229 3.66 55.86 3352 −90 380 470 250 0.240 3.84 53.47 3208 −59 544603 200 0.253 4.05 50.76 3046 −36 699 735 150 0.266 4.26 48.07 2884 −22826 848 100 0.282 4.51 44.64 2678 −8 966 974 50 0.295 4.72 42.73 2564 −30

[0112] TABLE 10 number of input side discharge side differential currentinput revolution pressure pressure pressure flow rate A W Hz rpm Vgf/cm² V gf/cm² gf/cm² V cc/min kg/h 0.286 4.58 39.06 2344 −162 157 319330 0.300 4.80 37.03 2222 −134 330 464 300 0.325 5.20 33.33 2000 −92 587679 250 0.351 5.62 30.12 1807 −66 828 894 200 0.384 6.14 26.10 1566 −39150 0.416 6.66 22.72 1363 −22 100 0.459 7.34 18.31 1099 −7 50 0.490 7.8415.33 920 −2 0

[0113] TABLE 11 number of input side discharge side differential currentinput revolution pressure pressure pressure flow rate A W Hz rpm Vgf/cm² V gf/cm² gf/cm² V cc/min kg/h 0.145 2.32 64.10 3846 2.398 33092.569 3545 236 4.52 271 11.22 0.160 2.56 59.17 3550 2.393 3303 2.6593669 366 3.05 183 7.58 0.193 3.09 56.17 3370 2.417 3335 2.742 3784 4492.26 136 5.62 0.250 4.00 45.45 2727 2.412 3329 2.818 3889 560 0.18 110.44

[0114] TABLE 12 number of input side discharge side differential currentinput revolution pressure pressure pressure flow rate A W V rpm V gf/cm²V gf/cm² gf/cm² V cc/min kg/h 0.150 2.40 3.99 3660 2.486 3431 2.630 3629198 5.24 315 13.03 0.160 2.56 3.85 3531 2.469 3407 2.649 3656 249 4.29257 10.65 0.170 2.72 3.75 3439 2.464 3400 2.704 3732 332 3.15 189 7.83

[0115] TABLE 13 number of input side discharge side differential currentinput revolution pressure pressure pressure flow rate A W Hz rpm Vgf/cm² V gf/cm² gf/cm² V cc/min kg/h 0.120 1.92 91.90 5514 2.550 35192.620 3616 97 5.00 300 12.42

[0116] The pump apparatus 1 makes use of the slide bearing members 5formed of the above-mentioned AC to support the rotating shaft 4, and sothe above-mentioned construction can realize a pump apparatus of highefficiency involving a small consumption power required for operation asshown in FIGS. 37 to 42 and Tables 5 to 13.

[0117] With the above-mentioned pump apparatus 1, the drive means 9drives the rotating shaft 4 to drive the pump body 10 connected to therotating shaft 4 so that the refrigerant sucked through the suction port33 can be made to flow down the flow passage 2 to be discharged from thedischarge port 43. The rotating shaft 4 is rotatably supported by thebearing apparatus 6 having the slide bearing members 5. The slidebearing members 5 are formed of amorphous carbon, which possesses theabove-mentioned properties and can support the rotating shaft 4 forsmooth rotation. Besides, amorphous carbon possesses high chemicalresistance and so is free of damage even in the case of being fittedinto the fluid flow passage. Further, the rotating shaft 4, the slidebearing members 5 and the rotor 7 are fitted into the flow passage 2.The gap between the rotating shaft 4 and the slide bearing members 5 isformed to be exceedingly small as described above to further stabilizerotation of the rotating shaft 4.

[0118] Such exceedingly small gap allows entering of liquid ammonia asthe refrigerant due to the capillary phenomenon. As AC possesses highchemical resistance, it is free of damage even in the case of beingfitted into the fluid flow passage. Also, the slide bearing members 5formed of AC are made irrespective of a kind of a fluid used, andaccordingly liquid ammonia can be made use of as a favorable lubricant.Accordingly, the pump apparatus makes it possible to make a refrigerantbeing fed, as a lubricant and to achieve smooth rotation of the rotatingshaft. Further, since the bearing structure 6 can be formed by means ofslide bearing members, it can be made simple and undergo less failure.

[0119] Also, AC is small in coefficient of friction to suppressgeneration of heat produced upon rotation of the rotating shaft 4 andcan prevent thermal expansion of the rotating shaft 4 and the slidebearing members 5. Besides, even if frictional heat generate, stablerotation could be maintained because AC is small in coefficient ofthermal expansion and the gap between the rotating shaft 4 and the slidebearing members 5 is not varied in dimension. Further, AC is small incoefficient of friction, so that with the above-mentioned small gapsmooth rotation is achieved even for fluids of high viscosity such asliquid ammonia. Also, owing to small wear, even in the long term use thefluid is prevented from being contaminated with abrasion powder and theabove-mentioned gap is prevented from being varied in dimension, so thatsmooth and stable rotation can be realized over a long term withoutmaintenance. Accordingly, the pump apparatus can be preferably mountedon equipment used in outer space outside the stratosphere to enhancedurability.

[0120] Also, provision of such rotating members in the housing 3 makesthe sealing property favorable and simplifies the construction therefor,thus enabling making the pump apparatus 1 small in size. Also, it ispossible to cool the rotating shaft 4, the slide bearing members 5 andthe rotor 7 to keep the stable performance of the pump. Further, thecylindrical-shaped member 11 is thin-walled to provide the coolingeffect of the stator 8 surrounding the rotor chamber 55. Besides, thedrive means 9 including the slide bearing members 5 and the rotor 7 islocated upstream of the pump body 10 in a flow direction of therefrigerant, so that the slide bearing members 5 and the rotor 7 can becooled in a state prior to compression by the pump body 10 and so astable and favorable cooling effect is obtained. In this manner, suchexcellent pump apparatus 1 can be realized.

[0121] Also, the pump body 10 is formed of amorphous carbon to be hardlysubjected to chemical influence by the fluid, and maintains the functionof the pump body over a long term to enable realizing a favorable pumpapparatus 1. Further, formation of the pump body 10 of amorphous carboncan have the pump body 10 fulfilling the function as thrust bearings andbearing thrust load of the rotating shaft 4. Therefore, load on theslide bearing members 5 can be reduced. In this manner, load is imposedon the pump body 10 to make it possible to reduce the slide bearingmembers 5 in size and enhance durability of the pump apparatus.

[0122] The above-mentioned embodiment is only exemplary of the inventionand can be modified within the scope of the invention. For example, theslide bearing members 5 may be one in number and three or more. Also,the fluid may be other one than liquid ammonia.

[0123] Also, the support apparatus and the pump apparatus may be used inother equipment, such as medical equipment, than equipment used in outerspace outside the stratosphere.

[0124] The invention may be embodied in other specific forms withoutdeparting from the spirit or essential characteristics thereof. Thepresent embodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription and all changes which come within the meaning and the rangeof equivalency of the claims are therefore intended to be embracedtherein.

What is claimed is:
 1. A support apparatus for displaceably supporting amovable member, comprising: slide members for slidably supporting themovable member, the slide members being formed of amorphous carbon. 2.The support apparatus of claim 1, wherein the movable member comprises arotating shaft and the slide members are slide bearing members forrotatably supporting the rotating shaft.
 3. The support apparatus ofclaim 1, wherein the slide members are arranged in a space in which afluid is contained.
 4. The support apparatus of claim 3, wherein a gapbetween the movable member and the slide members is dimensioned to allowentry of the fluid due to the capillary phenomenon.
 5. The supportapparatus of claim 3, wherein the fluid is liquid ammonia.
 6. Thesupport apparatus of claim 1, wherein the pump apparatus is mounted onequipment used in outer space.
 7. A pump apparatus comprising: arotating shaft; slide bearing members formed of amorphous carbon, forrotatably supporting the rotating shaft; drive means for drivinglyrotating the rotating shaft; and a pump body connected to the rotatingshaft, for pumping a fluid.
 8. The pump apparatus of claim 7, furthercomprising: a housing having a fluid flow passage which providescommunication between a suction port and a discharge port, wherein therotating shaft is arranged in the housing, the slide bearing members arefitted in the fluid flow passage in the housing, the drive meanscomprises a rotor fitted in the fluid flow passage to be provided on therotating shaft and a stator provided outside the housing to surround therotor, and the pump body is provided midway the fluid flow passage. 9.The pump apparatus of claim 8, wherein a gap between the rotating shaftand the slide bearing members is dimensioned to allow entry of the fluiddue to the capillary phenomenon.
 10. The pump apparatus of claim 9,wherein the pump apparatus is a pump for circulating a refrigerant andthe fluid is liquid ammonia as refrigerant.
 11. The pump apparatus ofclaim 10, wherein the pump body is formed of amorphous carbon.
 12. Thepump apparatus of claim 7, wherein the slide bearing members are radialbearings to bear radial load of the rotating shaft, and the pump body isformed of amorphous carbon to bear thrust load of the rotating shaft.13. The pump apparatus of claim 7, wherein the pump apparatus is mountedon equipment used in outer space.